I think the title of the topic speaks for itself, so I will add quite a bit (or even a lot). I’ve tried some shaderpacks with latest optifine, and I’ve found two issues (only one with gt though). It is about gregtech:gt.block.ocean and BuildCraft|Energy:blockOil, this blocks are rendering vanilla-style. So, I’ve fixed it, here are changed versions: RRe36_s_Shaders_v7_High_19_GT_SEA_WATER and Continuum-2.0.2_GT_SEA_WATER (extract to shaderpacks folder). Note, that RRe36 uses numeric blockID for detecting blocks by default, and I didn’t changed it for now, so you need to edit shaders/gbuffers_water.vsh (lines 118 and 132, replace blockID to correct one).
There are some issues right now, that I might fix (or not, if I will be too lazy). For example, line of nothing between sea water and river water (in continuum pack), oil is not black enough (this one might be tricky due to me being not good at all of this stuff). I hope, someone would find this useful)